Hmmm. I'm taking all this in. I pretty strongly resist the idea of going lighter with my hair, despite prevailing conventional wisdom.
Some time back, my MIL told my husband that she didn't like my hair dark, even though my natural color sans grey is quite dark brown (some forum members who have been around a while might remember that I briefly had much lighter highlights a few years ago, and my MIL definitely subscribes to the "coloring your hair lighter as you age" thing -- it's very much a thing especially in Texas). I never liked the way the lighter shade looked on me in photos -- it felt wrong, turned brassy very quickly, and the growout was more apparent with that color than it is now, when I'm covering my gray with a shade very very close to my natural color.
Immediately after a salon visit with my current color, I always feel like it's too dark, but it quickly softens up by a couple of shades. When I was going lighter with my hair color, I tended to go warmer and a bit more auburn, which I kind of liked, but I tired of it. And again, the growout always looked more obvious because you could see more of a line of demarcation between the cool toned roots with some grey and the warm-toned dyed hair. To go lighter with my natural hair tone would leave me with, I dunno, a washed-out ashy lighter brunette? That doesn't sound appealing. So I think for many people, going lighter means either going straight to grey/silver or going significantly warmer in tone, which is not always flattering or practical in terms of upkeep.
Again, interesting to think about, but I'm not sure what the answer is for me. In a recent hair thread I posted, I had a couple of suggestions to go lighter, but somehow that feels like taking some drama and edge away from my look.